Why do populations remain diverse? According some evolutionary theorists, it's because oddballs often enjoy advantages over their run-of-the-mill mates. A study of wild guppies now supports that idea. Biologists collected guppies from puddles in a forest in Trinidad and then redistributed them so that each puddle contained a small minority of males with color patterns very different from the rest. Sure enough, those outsiders were more likely to survive the next 2 weeks, the researchers report 31 May in Nature. They propose that predators, such as the killifish, may focus on the dominant color patterns and overlook the exceptions.